A wireless local area network (WLAN) is widely applied to homes, offices, and other indoor/outdoor environments. However, in indoor environments such as homes and offices, a horizontal coverage area and through-wall performance of an installed WLAN communications device, for example, an access point (also referred to as a hotspot) are important indicators that affect performance of a WLAN. Therefore, an adaptive switched-beam smart antenna with a high directive gain becomes extremely important in the WLAN communications device.
The following methods are available for implementing a smart antenna.
1. Different antennas or antenna arrays are selected using a radio frequency switch to perform radiation. Radiation directions of the antennas or antenna arrays are different, thereby implementing switching of antenna beams of a system.
2. An element and a feeding network are connected using a control switch, and different elements are selected by turning the control switch on or off, to perform radiation. Radiation directions of different elements are different, thereby implementing beam switching.
3. Reflectors in different directions are selected and connected using a control switch, thereby implementing beam switching.
However, these solutions have problems that a directive gain of an antenna is improved slightly relative to an omnidirectional gain, built-in and integration of an antenna array are difficult due to a large size, or the like.